Port Scanner
Run a quick TCP-connect scan against a host from Cloudflare’s edge across the 19 most common ports, or your own custom list, with per-port response times.
TCP-connect test from Cloudflare's edge, 1.5s timeout per port. An open port means something accepted the connection — it does not reveal the service version. Only scan hosts you own or have permission to test.
Scan a host’s common ports
Set the host to example.com and run a TCP-connect scan across the standard common ports to see which respond.
Requires completing the human-verification widget first — the example fills the host and triggers the scan, but you must pass the check for it to run.
FAQ
Is it safe or legal to scan?
Only scan hosts you own or have explicit permission to test. Unauthorized scanning may be against a host’s policy or local law, so restrict this tool to your own systems.
What do the results mean?
An “open” port means a service accepted the TCP connection. “Closed/no response” means nothing is listening or a firewall filtered it. This tool checks connectivity — it doesn’t report service versions.
Why do some scans need human verification?
Scanning public hosts could be abused, so a bot check (Cloudflare Turnstile) is required. Complete it, then press the scan button again.
How is this different from nmap?
This is a lightweight TCP-connect check of common ports from a single edge location. nmap is far more powerful (many techniques, hidden scanning, version detection) but heavier and not browser-based.